Synthesis,Structures And Catalytic Activities Of Main Group-and Transition-Metal Complexes Based On Pyrrolyl-Containing Schiff Base Ligands

This thesis reports the synthesis,structural characterization and catalytic activity of organometallic complexes based on pyrrolyl-containing Schiff base ligands.It includes the following four parts.In the first part,the pyrrolyl-containing Schiff base ligand H2L1(H2L1=N-[(1H-pyrrol-2-yl)methyl]-1-(1H-pyrrol-2-yl)methanimine)was synthesized.Two aluminum complexes A12(L1)zMe2(1)and Al2(L1)2Et2(2)were synthesized and their structures were determined by single crystal X-ray diffraction.Complexes 1 and 2 also have been characterized by NMR and elemental analysis.Both 1 and 2 can effectively catalyze the ring-opening polymerization of ?-caprolactone.In the presence of benzyl alcohol,the catalytic activities of 1 and 2 were significantly improved.In the second part,one pyrrolyl-containg asymmetric Schiff base ligand HL2(HL2=N-[(1H-pyrrol-2-yl)methyl]-1-[(1H-pyrrol-1-yl)-N,N-dimethylethan]methanimine)and three complexes Li2(nBu-L2)2(3),Mg2(nBu-H-L2)2(4)and Zn(L=)Et(5)have been synthesized.The crystal structures of 3-5 were determined by single crystal X-ray diffraction,NMR and elemental analysis.It was found that the ligand HL2 reacted with LinBu and MgnBu2,respectively,and the n-butyl group in LinBu and MgnBu2 was transferred to the the HL2 ligand,yielding new ligands nBu-L2 and nBu-H-L2,respectively.The catalytic activity of 3-5 toward the hydroboration of aldehydes(or ketones)was investigated.All complexes can effectively catalyze the reactions of aldehydes(or ketones)and pinacolborane at room temperature.The catalytic activity of lithium complex 3 and magnesium complex 4 were significantly higher than that of zinc complex 5.The yields of the reactions catalyzed by 3 or 4 can be as high as 99%in a very short time.In the third part,complexes Ti(L2)2(NMe2)2(6)and Zr(L2)2(NMe2)2(7)were synthesized and their structures were determined by single crystal X-ray diffraction.Complexes 6 and 7 exhibited high catalytic activities toward the intramolecular hydroamination of aminoalkene substrates.Lastly,three aluminum complexes A12(L2)Me5(8),Al(L2)2Me(9)and Al(L2)3(10)were synthesized.One dinuclear aluminum complex Al2(HL1)2(OBn)4(11)was also synthesized from the reaction of 1 with BnOH.The crystal structures of 8-11 were determined by single crystal X-ray diffraction,NMR and elemental analysis.